IMO, nothing under 700lbs. Do the lighter units work, sure or they would not be selling them for very long. But the heavier the better is basically the rule for anything that grades. As long as the tractor has the capabilities to raise the implement under a full load, you are good to go. People mention snow, is snow always light and fluffy, no. It gets hard and turns to ice. You need weight to break that up and move it.
The Land Pride RBT3584 is the perfect blade for your tractor IMO. I have recommended it for many of my customers with your size tractor, never had a complaint yet, other than why didn't I get this sooner?
Last suggestion, if you don't already have your tires loaded, get them loaded, all 4. I did that on my Mahindra 3215 HST, what a difference. Like a different-bigger tractor.